1. Technical Field
The present invention relates to a transfer device which transfers a toner image transferred to an image carrier belt to a transfer material such as paper, and to an image forming apparatus including the same.
2. Related Art
To date, in an image forming apparatus using a liquid developer, an image forming apparatus including a transfer device which transfers a toner image transferred to an image carrier belt to a transfer material, such as paper, has been proposed (for example, refer to a patent document JP-A-2001-166611). In a transfer device used in an image forming apparatus disclosed in the patent document, a transfer belt is rotatably wound on two rollers, and brought into pressure contact with an opposite roller via an image carrier belt, forming a long nip.
In the transfer device described in the patent document, a configuration for stably driving the transfer belt is not disclosed.
In the transfer device using the liquid developer, in a case of adopting a configuration such that the transfer belt is moved in conjunction with the image carrier belt, a problem occurs in that it is not possible to obtain a stable conjoined movement due to a reduction in friction coefficient in a long nip portion caused by a burden due to a cleaning of the transfer belt, or by an encroachment of a remaining toner or carrier into a belt underside. Unless it is possible to obtain the stable conjoined movement of the transfer belt, carriers or toners become likely to be deposited at a transfer nip entrance, and there is a possibility of soiling the transfer material.